BIO 3422 Lecture Notes - Lecture 1: Membrane Transport Protein, Walter Bradford Cannon, Tight Junction
Document Summary
Cell fluid types (cid:2) (cid:2) (cid:2) (cid:2) Extracellular: interstitial and plasma (within blood vessel: creates an internal environment for cells (bernard) Coordinated physiological processes work together to maintain a relatively steady state in an organism. Phospholipid molecules (cell membrane: lipid bilayer; mostly nonpolar) Head (hydrophilic) and long c tail (hydrophobic/lipophilic) Integral: integrated into cm: trans-membrane: goes completely through (channel) Peripheral: inside of cell membrane (not in membrane) Desmosome: holds cells firmly together providing mechanical strength; anchored together; localized; helps prevent being pulled apart: ex: skin (blister=disruption) Gap junction: provides direct pathway for communication: important in rapid transmission of electrical signals, epithelium: cells that are bound together. Lipids can go through membrane no problem. Hydro"s have issues; must go between the cells (due to polar membrane of cells) Net flux (movement of molecules over a membrane over a given amount of time) increases with concentration gradient. Permeability, thickness of membrane, surface area, size affects this: simple:
